Ch 2 Flashcards
did you ever wonder how fatty acids relate to health
and disease?
identify the main chemical elements of the human body
describe the structures of atoms
describe the structure of ions
describe the structure of molecules
describe the structure of free radicals
describe the structure of compounds
matter
anything that occupies space- all living and nonliving things consist of matter
mass
the amount of matter in any object, which does not change
weight
the force of gravity acting on matter, does change
chemical elements
all forms of matter- living and nonliving made up of a limited number of building blocks this is chemical element
chemical symbol
1 or 2 letters of the elements name in different language, ex- H-hydrogen
major element
twenty-six different chemical elements normally present in your body, 4 major elements 96% of the body’s mass, oxygen, carbon, hydrogen, and nitrogen
lesser elements
contribute to 3.6% of bodys mass, calcium, phosphorus, potassium, sulfur, sodium chloride, magnesium, iron
trace elements
present in tiny amounts- account for 0.4% body’s mass, example would be iodine- needed to make thyroid hormones
oxygen
65% body mass-part of water and many organic molecules, used to generate ATP, a molecule used by cells to temporarily store chemical energy
carbon
18.5% body mass- forms backbone chains and rings of all organic molecules; carbohydrates, lipids(fats), proteins and nucleic acids (DNA and RNA)
hydrogen
9.5% body mass- constituent of water and most organic molecules, ionized from H+, makes body fluids more acidic
nitrogen
component of all proteins and nucleic acids
subatomic particles
3 main subatomic particles for chemical reactions in the human body, protons, neutrons and electrons
subatomic particles
3 main subatomic particles for chemical reactions in the human body, protons, neutrons and electrons
nucleus
dense central core of an atom
protons
P+- a stable subatominc particle occuring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but opposite sign
protons
P+- a stable subatomic particle with positive charge
electrons
e-= subatomic particle with a negative charge
neutrons
n0- uncharged or neutral subatomic partical
electron shells
regions (circles) around nucleus
How are the electrons of carbon distributed between the
first and second electron shells?
mass number
sum of protons and neutrons
isotopes
atoms of element that have different numbers of neutrons and therefore different mass number
radioactive isotopes
unstable isotopes, their nuclei decay into a stable configuration- ex H-3, as they decay, they omit radiation either subatomic partials or packets of energy, and in the process transform into different element
half-life of an isotope
the time required for half of the radioactive atoms in a sample of that isotope to decay into a more stable form
compound
a substance that contains atoms of two or more different elements
free radical
an atom or group of atoms with an unpaired electron in the outermost shell- ex- superoxide
atomic mass (atomic weight)
of an element is the average mass of all its naturally occurring isotopes
ion
an atom that has a positive or negative charge because it has unequal numbers of protons and electrons
ionization
the process of giving up or gaining electrons
molecule
two or more atoms share electrons, the resulting combination is molecule
how are atomic number, mass number, and atomic mass of carbon and how are they related
List the names and chemical symbols of the 12 most abundant
chemical elements in the human body
oxygen O
carbon C
hydrogen H
nitrogen N
calcium Ca
Phosphorus P
potassium K
sulfur S
sodium Na
Chlorine Cl
magnesium Mg
iron Fe
what substance in the body can inactivate oxygen derived free radicals?
chemical bonds
the force that hold together the atoms of a molecule or a compound
valence shell
outermost shell of an atom, the electrons in this shell take part in bonding with other atoms
ionic bond
the force of attraction that holds together ions with opposite charges
cation
a positivly charged ion
cation
a positively charge ion- sodium ion Na+
anion
a negatively charged ion- ex- iodine ion I-
electrolyte
ionic compound that breaks apart into positive and negative ions in solution
covalent bond
two or more atoms share electrons rather than gaining or Losing them
single covalent bond
results when two atoms share one electron pair
what is the main difference between an ionic bond and a covalent bond
double covalent bond
results when two atoms share two pairs of electrons- oxygen molecule
triple covalent bond
occurs when two atoms share three pairs of electrons - ex- molecule of nitrogen
nonpolar covalent bond
when atoms chare two electrons equally- one atom does not attract the shared electrons more strongly than the other atom
polar covalent bond
the sharing of electrons between two atoms is unequal - the nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom-ex- A very important example of
a polar covalent bond in living systems is the bond between oxygen
and hydrogen in a molecule of water
electronegativity
the power to attract electrons to its self
hydrogen bond
forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of the neighboring electronegative atoms, most often larger oxygen or nitrogen atoms
surface tension
the tendency of liquid surfaces at rest to shrink into the minimum surface area possible- it allows objects with higher density than water such razor blades float on water surface without becoming even partly submerged
Why would you expect ammonia (NH3) to form hydrogen
bonds with water molecules?
cohesion
the action or fact of forming a united whole
which electron shell is the valence shell of an atom, and what is
its significance?
Compare the properties of ionic, covalent, and hydrogen bonds
what information is conveyed when you write the molecular or
structural formula for a molecule?
chemical reaction
occurs when a new bonds form or old bonds break between atoms
enegry
is the capacity to do work
potential energy
energy stored by matter due to its position
kinetic energy
the energy associated with matter in motion
chemical energy
form of potential energy that is stored in the bonds of compounds and molecules
law of conservation of energy
Conversion of energy from one form to another
generally releases heat, some of which is used to maintain normal
body temperature.
exergonic reaction
release more energy than they absorb
endergonic reactions
absorb more energy than they release
activation energy
the collision energy needed to break the chemical bonds of the reactants
concentration.
the more particles of matter present in a confined
space, the greater the chance that they will collide
temperature
temperature rises, particles of matter move about
more rapidly.
catalysts
chemical compounds that speed up chemical reactions by lowering
the activation energy needed for a reaction to occur
reversible Reactions
the products can revert to the original reactants, A reversible reaction is indicated by two half-arrows pointing in opposite directions.
anabolism
all of the synthesis reactions that occur in the body are collectively referred to as anabolism
Oxidation
refers to the loss of electrons; in the process
the oxidized substance releases energy
reduction
to the gain of electrons; in the process the reduced substance gains energy
oxidation–reduction reactions
are always parallel; when one substance is oxidized, another is reduced at the same time.
what is the relationship between reactants and products in a chemical reaction
compare potential and kinetic energy
how do catalysts affect activation energy
why are oxidation- reduction reactions important
exchange reaction
the consist of both synthesis and decomposition reactions
decomposition reaction
split up large molecules into smaller atoms, ions or molecules
solvent
able to dissolve other substances
solution
liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (solvent)
solute
the minor component in a solution, dissolved in the solvent
hydrophilic
water loving- dissolve easily in water
hydrophobic
water fearing - not very water soluble
Inorganic compounds
usually lack carbon and are structurally simple.
Organic compounds
always contain carbon, usually contain hydrogen, and
always have covalent bonds
Water
the most important and abundant inorganic compound in
all living systems, die in a matter of days without water
hydrolysis
to loosen or break molecules, which would increase the waters temperature
ubricating fluids
Water is a major component of mucus and other lubricating fluids throughout the body. Lubrication is especially necessary in the chest (pleural and pericardial cavities) and abdomen (peritoneal cavity), where
internal organs touch and slide over one another.
heat of vaporization of water is high
Water also requires a large amount of heat to change from
a liquid to a gas.
mixture
combination of elements or compounds that are physically blended together but not bound by chemical bonds
colloid
a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance
dehydration synthesis reaction
combination or synthesis reactions which occur between the same or deferent monomer units with the elimination of water molecules
Thermal Properties of Water
In comparison to most substances, water can absorb or release a relatively large amount of heat with only a modest change in its own temperature. For this reason, water is said to have a high heat capacity. The reason for this property is the large number of hydrogen bonds in water
concentration pg 51
percentage
base
proton donor
proton acceptor
hydroxide ions (OH-)
salt
mole
acid
buffer system
buffers
carbonic acid bicarbonate buffer system
macromolecule
macromolecule
polymer
monomoer
isomer
how do inorganic compounds differ from organic compounds
describe 2 ways to express the concentration of a solution
what functions does water perform in the body
how do bicarbonate ions prevent buildup of excess H+
which functional group helps stabilize the shape of proteins
functional groups
carbon skeleton
hydrocarbon
carbohydrates
glycogen
monosaccharides
disaccharide
polysaccharide
how are carbohydrates classified
how are dehydration synthesis and hydrolysis reactions related
lipids
lipoproteins
saturated fats
glycerol
saturated fatty acid
monounsaturated fats
polyunsaturated fats
phospholipids
steroids
4 rings of carbon atoms, cholesterol- cell membrane structure, estrogen, and testosterone- regulating sexual funtions, cortisol- normal blood sugar levels, bile salts- needed for lipid digestion and absorption, vitamin D- bone growth
eicosanoids stopped on page 59
lipid derived from 20- carbon fatty acids called arachidonic acid
leukotrienes
participate in allergic and inflammatory responses,
proteins
large molecule that contains carbon, hydrogen, oxygen and nitrogen. some contain sulfur, 12-18% protein in adult. enzymes are proteins that speed up most biochemical reactions, some drive muscle contraction, antibodies- defend against invading microbes
table 2.8
long chains of amino acids are proteins
peptide bond
covalent bond joining each pair of amino acid, always forms between carbon and carboxyl group (-COOH)
polypeptide
help make up proteins by bonding numerous amino acids together
peptide
short chains of amino acids linked by peptide bonds
denaturation
no longer functional protein, when protein encounters a altered environment, it may unravel and lose its characteristic shape
enzyme
catalysts are protein molecules- consist of 2 parts- apoenzyme (protein portion) and cofactor (nonprotein portion)
An enzyme speeds up a chemical reaction without being altered or
consumed.
enzymes are highly specific
Each particular enzyme binds only to
specific substrates
enzymes are very efficient
they can catalyze reactions at rates that are from 100 million to 10 billion times more rapid than those of similar reactions occurring without enzymes
Enzymes are subject to a variety of cellular controls.
Their rate of synthesis and their concentration at any given time are under the control of a cell’s genes
how enzymes work
The substrates make contact with the active site on the surface
of the enzyme molecule, forming a temporary intermediate compound called the enzyme–substrate complex. In this reaction the two substrate molecules are sucrose (a disaccharide) and water.
2 The substrate molecules are transformed by the rearrangement
of existing atoms, the breakdown of the substrate molecule, or
the combination of several substrate molecules into the products
of the reaction. Here the products are two monosaccharides:
glucose and fructose.
3 Aft er the reaction is completed and the reaction products move
away from the enzyme, the unchanged enzyme is free to attach to
other substrate molecules.
nucleic acids
organic molecule that contains C, H, N, O, P, 2 varieties DNA (deoxyribonucleic acid) forms inherited genetic material inside each human cell
RNA (ribonucleic acid)- relays instructions from the genes to guide each cells synthesis of proteins from amino acids
nucleotides
has 3 parts
itrogenous base. DNA contains four diff erent nitrogenous
bases, which contain atoms of C, H, O, and N. In DNA the four
nitrogenous bases are adenine (A), thymine (T), cytosine (C), and
guanine (G). Adenine and guanine are larger, double-ring bases
called purines (PŪR-ēnz); thymine and cytosine are smaller,
single-ring bases called pyrimidines (pī-RIM-i-dēnz). The
nucleotides are named according to the base that is present. For
instance, a nucleotide containing thymine is called a thymine
nucleotide, one containing adenine is called an adenine
nucleotide, and so on.
2. Pentose sugar. A five-carbon sugar called deoxyribose attaches to
each base in DNA.
3. Phosphate group. Phosphate groups (PO4
3−) alternate with
pentose sugars to form the “backbone” of a DNA strand; the bases
project inward from the backbone chain .
double helix
spiral ladder of 2 strands of alternation phosphate group and deoxyribose sugars from the uprights of the ladder.
how do DNA and RNA differ
DNA- self replicating, has double helix, A with T, G with C
encodes information for making proteins
RNA- made by using DNA as blueprint, on strand, A with U, G with C
carries the genetic code and assists in making proteins
what is a nitrogenous base
molecule that contains nitrogen and has the chemical properties of a base
ATP- adenosine triphosphate
energy currency of living systems, is the principal energy-transferring molecule in living systems.
ADP- adenosine diphosphate
In the reaction catalyzed by ATP synthase, what are the
substrates and products? Is this an exergonic or endergonic
reaction?
